What costs society a quadrillion dollars of lost value? Not educating the poor! This is much bigger than the damage done by the worst nightmares models of any global warming. On par with WW3 in lost value. So it is nice to see it getting summarized in this article. On a personal note, my father was the guy who first did the economics analysis of the Perry Preschool project. Basically the curious fact which seems to keep getting rediscovered is that preschool helps later life outcomes. It doesn't help 2nd grade--but it does help finding a job. My personal view is that it would help the 2nd grade marshmallow test which is one of the best predictors of future success in life. But this experiment hasn't been run to my knowledge.